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E_Snap t1_isnqxu9 wrote

Reply to comment by tiregroove in Ultrathin polymer-based ordered membranes that effectively remove salt from seawater and brine could provide a promising alternative to existing water desalination systems by giuliomagnifico

You stop intentionally extracting salt from other sources and use the salt that you get from this process instead. Convert sea salt farms to use wastewater from these. Use it as a chemical feedstock if eating it gives folks the willies.

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Grapesoda5k t1_isob8xw wrote

Its not that simple. The brine created from desalination is toxic.

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ArmadilloReasonable9 t1_isp2oel wrote

It’s toxic because of the concentration if it was evaporated it’d still just be sea salt.

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Grapesoda5k t1_isp2wgh wrote

That's not what toxic means.

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ArmadilloReasonable9 t1_isp5lo0 wrote

That’s exactly what it means, there’s a safe amount of any substance. A substance is toxic when it harms an organism. You can’t just eat sea salt, even water is toxic when you drink enough of it to dilute you blood to the point your cells swell and burst.

This brine is toxic because it is saltier than the local ecosystem is able to tolerate, and can displace seawater forming pools that hang around.

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Grapesoda5k t1_isp6kik wrote

Not in this case. You're making parallel arguments based on nothing.

Not one source has supported your argument in the desalination discussions.

https://news.mit.edu/2019/brine-desalianation-waste-sodium-hydroxide-0213

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ArmadilloReasonable9 t1_isp84xj wrote

There was no mention of toxicity in that article? Dissolution of NaCl in H2O produces Na+, Cl-, OH- and H+ ions. These can form sodium hydroxide and hydrochloride acid. The article supports what I said saying that careful discharging into the ocean is safe if properly managed.

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Grapesoda5k t1_ispbwq1 wrote

"If" isn't a response you can trust from a corporation.

And notice none of the solutions being done say this stuff is safe for human consumption.

If it was the waste wouldn't be an issue.

So it's not a matter of concentration.

And needing careful consideration in handling the bi-products argues its not just hi-test salt.

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tiregroove t1_isntu0k wrote

Did you not read the link? Desalinization plants create overwhelming unsustainable and TOXIC levels of salt, LITERALLY the size of Florida EVERY YEAR, with nowhere to put it all, on a level that's killing marine life.
More than half from Saudi Arabia.

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hiraeth555 t1_isnwy9t wrote

Make those lamps out of the excess salt and give them out for free

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SuspiciousStable9649 t1_isnyb2h wrote

Color it sky blue and call it ‘Arabian Salt’.

Edit: but seriously is cheapest to just wash it back out to sea.

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Uptown-Dog t1_isox16o wrote

Yeah, we know that's the cheapest option and so that's why everyone does that rn.... Except it kills marine life and creates dead zones where that's done because it's too salty for anything alive.

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Garbage_Wizard246 t1_isp1msu wrote

Salt can be used to fuel nuclear reactors and an easy material for batteries. There are other solutions people

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Uptown-Dog t1_isp2a08 wrote

I'm all for other solutions. But AFAICS no one doing desalination is getting down to pure salt as it's not cost effective. Rather they stop at "toxic brine". Otherwise I don't see why they couldn't just create and pack all the bricks of salt in a storage setup and work from there.

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Garbage_Wizard246 t1_isp5knm wrote

It can be subsidized if the correct supply chain is set up following it. I'm hoping salt batteries take off soon and if we have good infrastructure they can compliment each other in the bid to go green

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Tlaughs t1_isqwgpy wrote

Recent research suggest this isn't true if it's pumped out to blue ocean it dilutes to nontoxic levels extremely quickly

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Uptown-Dog t1_isqx2u5 wrote

Do you have a link available? Also, how far out qualifies as "blue ocean"? It would almost certainly be contingent upon currents too, as otherwise it would build up? I would also be curious as to how rigorous the science is, as opposed to "we pushed it out of sight and we're bad enough at detecting life there that no one is able to call us out at this stage for killing things there".

Which isn't to say that I'm not encouraged to hear that - and maybe there's an argument to be made that life close to shore is more important than life further out?? - but it needs to be sustainable.

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Tlaughs t1_isvuorj wrote

I don't, it came up months ago in a similar post to this one, and they had sources which I do not.

It might very well have been the latter part of what you said, marine life is overwhelmingly close to shore or other landmarks like reefs/wrecks/vents. When it is pumped out into open ocean the currents can fully reach and disperse it, with a fraction of marine life within the (reduced) zone in which the salts are toxic. It all came from the ocean, and despite the massive volumes that are desalinated, it's not a meaningful increase in concentration.

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youritalianjob t1_iso9r42 wrote

You act like the amount of salt we extract for consumption and other uses isn’t a large amount.

Currently we extract about 290 million metric tons a year.

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OfLittleToNoValue t1_isnyjxe wrote

Global warming is raising sea levels. Desalinate the water and drink it to lower sea level. Put salt where the glaciers were. Easy.

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CroatianBison t1_iso5my2 wrote

Salt is white, glaciers are white, I see no flaw with this plan. Nobody will notice the difference

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smohan t1_isofftx wrote

I wonder of the color itself might help, cos I remember reading that reflection of solar rays by ice caps helps lower temperature.

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Snuffy1717 t1_isodymn wrote

Also, we all know that salt makes ice colder so in doing this we've solved the ice melt problem!

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ArmadilloReasonable9 t1_isp3tze wrote

It’s sea water with a 15% higher concentration of salt, the brine just needs to be well dispersed and released slowly and it won’t cause any issues to the environment. That article was a mess.

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Holden_SSV t1_isqem2i wrote

Snow removal contractor here. We make our own salt brine for pre treatment of ice storms or even snowfall. 18% is our good to go number.

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ArmadilloReasonable9 t1_issdv9o wrote

18% salt by weight? This stuff is 5% salt by weight, 15% higher than sea water. Sadly there probably wouldn’t be many desalination plants near areas that have to salt their roads.

There are definitely uses for it but they’re all pretty impractical until we’ve got excess renewable energy capacity to pump it further or use electrolysis to separate the different ions.

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Strazdas1 t1_isswq5l wrote

noone needs to salt thier roads. Its a terrible practice that destroys cars, shoes and plantlife that this brine gets onto. Just use small gravel like norway does.

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Strazdas1 t1_issweva wrote

how about, and i know this is a radical thought, put the salt back where you pumped it from?

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